Hermetically sealed containers that incorporate pierceable membranes that are to be pierced by a draining spike are known in the art and are illustrated by U.S. Pat. No. 4,901,873 to Weiler and U.S. Pat. No. 5,595,314 to Weiler. Such containers utilize a separately fabricated closure insert, and are useful in applications where the container contents is dispensed through a nozzle affixed to the container as the membrane is pierced or thereafter. U.S. Pat. No. 6,571,971 to Weiler illustrates a closure insert that provides a primary seal about a draining spike in the form of a peripheral sealing band or bead carried by a downwardly depending skirt portion downstream from the pierced membrane. The pierced membrane then serves as a partial secondary seal.
From the standpoint of cost and manufacturing expediency it would be desirable, however, to dispense with the need for a separately fabricated closure insert when making hermetically sealed thermoplastic containers, the content of which can be accessed utilizing a draining spike.
The fabrication of a seal such as that shown in the aforementioned U.S. Pat. No. 6,571,971 is not possible, however, when the container closure is not a separate insert but is unitary with an fabricated concurrently with the molding of the container itself.